2009 Yamaha Motorsports RS Viking Professional Owners Manual - Page 49
2009 Yamaha Motorsports RS Viking Professional Manual
Page 49 highlights
Periodic maintenance and adjustment TIP After riding the snowmobile, make sure that there is no snow under the air filter element frame. ESU11910 Carburetors The carburetors are an important part of the engine and its emission control system, which require very sophisticated adjustment. Therefore, carburetor adjustments should be left to a Yamaha dealer, who has the necessary professional knowledge and experience. ESU11941 2. 3. Remove the air filter case cover. Lift up the air filter element frame and check the air filter element. If there is any snow on the air filter element, remove the element, brush off the snow, and then install the air filter element. High-altitude settings Operating at high altitude reduces the performance of a gasoline engine about 3% for every 305 m (1000 ft) of elevation. This is because there is less air as altitude increases. Less air means less oxygen available for combustion. Your snowmobile can be adjusted to overcome most of the problems found in high-altitude riding. Carburetor adjustments are the most important. Less air at high altitude makes the air/fuel ratio too rich, which can cause poor performance. Common problems are hard starting, bogging, and plug fouling. Proper carburetion adjustments will correct the air/fuel ratio. Be sure to have a Yamaha dealer make these adjustments. Remember: Less air at higher altitude means there is less horsepower available, even with proper carburetion. Expect acceleration and top speed to be reduced at higher altitudes. To overcome operating with less power at high altitudes, your snowmobile may also require different settings for the drive chain gears and V-belt clutch to avoid poor performance and rapid wear. If you plan to operate your snowmobile at an altitude different from the area where you bought it, be sure to con- 4. 5. Place the air filter element frame in the original position, and then install the air filter case cover. Install the air filter case cover by hooking the fasteners. 43